Every good 'n'grizzled commander knows to pick his Lieutenants well. The past two years have been something of a golden period for Nick Cave; judging moustache contests, giving out the Turner Prize, not to mention the feral Grinderman set upon a supine, willing audience and this year's new Dig, Lazarus, Dig!!! marking a welcome return to a rawer Bad Seeds sound. Yet Cave is always quick to insist that he is not a solo artist. Since the departure of Blixa Bargeld in 2003, Warren Ellis seems to have found a greater voice within the Bad Seeds set-up and beyond, be it in his role in Grinderman, or working on film soundtracks with Cave. The sounds he wrings from violin and those tiny, yet full-throated, guitars gave Grinderman its lustre, his picking raises Lazarus, his onstage high-kicking complimenting Cave's twisted evangelical, seam-busting gesturing. The Quietus called Ellis to reflect on the peculiar alliance between Grinderman and the Bad Seeds, his relationship with the group, and just what the hell else he's been up to in this 2008. It's been a busy old year has it, Warren? "Fuck, tell me about it man..."

So to start, how was it unleashing Grinderman on the festival crowds this summer?

This festival run was really enjoyable. The band seems made for the festivals, the way we play. It's a very different thing, just the four of us going on to play with no soundcheck or any of that boring stuff, which actually seems to help the performance with Grinderman in some ways. All hell breaks loose up there. We've found the songs and it's loosened up a whole lot more and we're looking at different ways of playing them, not just discovering them.

You said that Grinderman would have an impact on the Bad Seeds, do you think post-Dig, Lazarus, Dig!!! that's going to work the other way round too?

I think so. It's not like we go in there in a different mood or a different headspace. When we went in to record that Grinderman album we didn't even have a name for it. You couldn't imagine how liberating that was if you tried. A big part of the whole thing was to not have any identity - obviously you can't start from zero again, and it's pointless to even think that you could, but to go in there not even having a name was a real reminder of how many restrictions you unwittingly put on yourself, particularly with a group like the Bad Seeds where there's such a long history. The Bad Seeds, particularly before I joined, flew in the face of what was considered to be the norm for rock music, and that was part of their thing. You'd never find a guitar solo on a Bad Seeds record, it was anti a lot of that stuff, to their credit. I guess we've tried to open doors on things that wouldn't be liked.

Do you feel like perhaps you've come to the fore more in terms of the Bad Seeds dynamic?

I was never particularly into playing just the violin. When I started with the Dirty Three that was always what was that great thing about it, we wanted to be free from the instruments, and I'd never play a straight violin line. So joining the Bad Seeds was a rather odd proposition for me because I'd never been in that position before, and it would arise that I'd have to do that sort of thing. Then I guess by playing these other instruments it changed my involvement. I've been working on Nick on so many varied projects now, and up to this point it's going good. It's like when you meet somebody and you have a chat and realise you get on with them, so you meet up again and six months later that might grow into something quite different. And music is a bit like that too, you find you get on with somebody, and you find you might want to spend more time with them. What I like about working with Nick is he tries to push me as far as I can go, he doesn't try to hold me back and that's really encouraging.

How does that work in the wider Bad Seeds group?

It's good because within that environment you can fall flat on your face and realise that it doesn't matter. It's good to go as far as you can go before you realise it's not working, because sometimes it can work, you know? I guess it encourages even the most ridiculous-sounding idea to be carried through to whichever conclusion it could go to. I really like that. It's about taking chances. In the Bad Seeds it seems like people go in and do what they do, and sometimes people are required to do more or less, and it's not even a discussed thing.

Nick Cave & The Bad Seeds: 'Night Of The Lotus Eaters'

You've also done the music for a series of Sony adverts. How was that?

I was doing it ten days before the Bad Seeds were going on tour and it was a total meltdown experience. You'd present it and they'd be saying 'We love it, we love it', then you get a phone call as you're walking out of the door saying 'we just presented it to the heads of Sony and they don't like it'. You've got fifty minutes to do a new thing before we present it again'. I just went 'you're fucking joking' and smashed the phone into pieces.

Warren Ellis' music for the Song advert:

Would you put yourself through that again?

It's not the sort of thing I'd want to do all the time, I wouldn't say it was incredibly rewarding, it's not like playing in front of a couple hundred people. It's only been in the past couple of years that I've actually started enjoying the studio, and getting more involved in that. Before, it was always more about playing live - it's just fantastic, that whole experience. I love playing with people we know, I love playing in a band, and I love that thing of performing music. It sounds like a corny thing to say, but it's just an incredible escape you know, all the stuff getting fucked up and shit-faced, it's fantastic. You work your way through all that and work out where you want to be if you're still going with it.

How does that relate to the different groups you're in?

It's really great, it just helps with what you're doing. Someone like me, I don't like songs, I somehow seem to have been part of writing quite a lot of material now for some reason, and I found doing all these different thing has really helped whatever I'm going on to do next. Playing in the Dirty Three has helped with the Bad Seeds, then the Bad Seeds helped with the Dirty Three. Whatever you do, if you're trying to do something different the next time you're trying to modify things a whole lot and it's really invigorating.

Does it stop you getting stuck?

Aside from the whole thing about the music there's an incredible dynamic to a band, being around the same people all the time, and it's a real relief to have different things going on.

Do all you Bad Seeds still get on?

Every bunch of people like that if you have problems you either work it out or you don't and you split up. It's something that you don't really think about until it happens and you find yourselves together, it's like having a girlfriend or a boyfriend, the intensity of the relationship. It's something you realise after two years of touring non-stop with the Bad Seeds: fuck me, I'm living with these people.

Coming on the Quietus in 2009: Warren Ellis on shoes, socks and personal grooming. Warren Ellis live shots by Shot2bits